Surgical instruments with sensors for detecting tissue properties, and system using such instruments

ABSTRACT

A system is provided that furnishes expert procedural guidance based upon patient-specific data gained from surgical instruments incorporating sensors on the instrument&#39;s working surface, one or more reference sensors placed about the patient, sensors implanted before, during or after the procedure, the patient&#39;s personal medical history, and patient status monitoring equipment. Embodiments include a system having a surgical instrument with a sensor for generating a signal indicative of a property of a subject tissue of the patient, which signal is converted into a current dataset and stored. A processor compares the current dataset with other previously stored datasets, and uses the comparison to assess a physical condition of the subject tissue and/or to guide a procedure being performed on the tissue.

FIELD OF THE INVENTION

The present invention relates to surgical instruments, specifically tosurgical instruments with sensors used to detect properties ofbiological tissue, and a system for exploiting the information gatheredby the sensors.

BACKGROUND ART

A living organism is made up of cells. Cells are the smallest structurescapable of maintaining life and reproducing. Cells have differingstructures to perform different tasks. A tissue is an organization of agreat many similar cells with varying amounts and kinds of nonliving,intercellular substances between them. An organ is an organization ofseveral different kinds of tissues so arranged that together they canperform a special function.

Surgery is defined as a branch of medicine concerned with diseasesrequiring operative procedures.

Although many surgical procedures are successful, there is always achance of failure. Depending on the type of procedure these failures canresult in pain, need for re-operation, extreme sickness, or death. Atpresent there is no reliable method of predicting when a failure willoccur. Most often the failure occurs after the surgical procedure hasbeen completed. Failures of surgical procedures can take many forms. Themost difficult failures to predict and avoid are those that involvebiological tissue. This difficulty arises for three distinct reasons.Firstly, the properties that favor the continued function of biologicaltissue are very complex. Secondly, these properties are necessarilydisrupted by surgical manipulation. Finally, the properties ofbiological tissues vary between people.

During a surgical operation, a variety of surgical instruments are usedto manipulate biological tissues. However, traditional surgicalinstruments do not have the ability to obtain information frombiological tissues. Obtaining information from the biological tissuesthat surgical instruments manipulate can provide a valuable dataset thatat present is not collected. For example, this dataset canquantitatively distinguish properties of tissues that will result insuccess or failure when adapted to specific patient characteristics.

Surgical instruments that incorporate sensors onto the instruments'working surfaces are described, e.g., in U.S. patent application Ser.No. 10/510,940 and in U.S. Pat. No. 5,769,791. The instruments describedin the prior art have the ability to sense tissue properties; however,their utility is limited by an inability to account for the multitude ofdifferences that exist between patients. This limitation of the priorart is clearly illustrated by the fact that the instruments generatefeedback after sensor signals are compared to a fixed dataset within thedevice. Thus, the prior art instruments have no means of adapting topatient-specific characteristics that are of utmost importance inavoiding surgical procedure failure.

There exists a need for a system and methodology for using theinformation gathered by surgical instruments having sensors in anadaptive, patient-specific manner. There also exists a need forinstruments having sensors that are useful for monitoring a patient'scondition during and after surgery.

SUMMARY OF THE INVENTION

An advantage of the present invention is a system which generates realtime, patient specific procedural guidance for predicting success of asurgical procedure, and avoiding or detecting failure of the procedure.Another advantage of the present invention is a system which recordsdata across the entire patient encounter including pre-operative,intra-operative and post-operative periods, as well as immediate, acute,short term, and long term outcomes both locally in hospital-based unitsas well as remotely in a data repository.

A further advantage of the present invention is a system which providesexpert procedural guidance based upon patient specific data gained frompersonal medical history, patient status monitoring equipment, surgicalinstruments incorporating sensors on the instrument's working surface,reference sensors placed about the patient, and implanted sensors placedbefore, during or after the procedure.

A still further advantage of the present invention is a system whichgenerates patient specific expert guidance in optimizing surgicalprocedures based upon statistically matched data from a centralrepository. Yet another advantage of the present invention is a systemwhich adapts its guidance based on continuously updated, statisticallysignificant data.

According to the present invention, the foregoing and other advantagesare achieved in part by a system comprising a surgical instrument havinga sensor for generating a signal indicative of a property of a subjecttissue of a patient; a signal processor for receiving the signal andconverting the signal into a current dataset; a memory for storing thecurrent dataset; and a processor. The processor is configured to comparethe current dataset with other datasets previously stored in the memory,and to assess a physical condition of the subject tissue or guide acurrent procedure being performed on the tissue, responsive to thecomparison.

Another aspect of the present invention is a system comprising asurgical instrument comprising an incident light source and a sensor forusing incident light from the light source to generate a signalindicative of fluorescence of a subject tissue into which a fluorescentmedium has been introduced; and a processor configured to receive thesignal and to determine a tissue characteristic of the subject tissueresponsive to the response of the fluorescence as indicated by thesignal.

A further aspect of the present invention is a sensor consistingessentially of a rigid or flexible substrate and a plurality of sensingelements mounted to the substrate for monitoring a property of a livingtissue.

A still further aspect of the present invention is a surgical fasteningdevice comprising a sensor for measuring properties of and interactionwith a living tissue on the fastening device.

A further aspect of the present invention is a system comprising asurgical instrument having a sensor for generating a signal indicativeof a property of a subject tissue of a patient; a reference measurementinstrument having a sensor for measuring a reference tissue andgenerating a reference measurement signal; a signal processor forreceiving the signal and converting the signal into a current dataset,and for receiving the reference measurement signal and converting itinto a current reference dataset; a memory for storing the currentdataset and the current reference dataset; and a processor. Theprocessor is configured to compare the current dataset with the currentreference dataset, and to assess a physical condition of the subjecttissue and/or guide a current procedure being performed on the tissue,responsive to the comparison.

Another aspect of the present invention is a system for monitoring aliving tissue of a patient's body, comprising a sensor implantable inthe patient's body for generating a signal indicative of a property ofthe tissue; a controller for receiving the signal outside the patient'sbody; and a communications interface for communicating the signal fromthe sensor to the controller.

Additional advantages of the present invention will become readilyapparent to those skilled in this art from the following detaileddescription, wherein only selected embodiments of the present inventionare shown and described, simply by way of illustration of the best modecontemplated for carrying out the present invention. As will berealized, the present invention is capable of other and differentembodiments, and its several details are capable of modifications invarious obvious respects, all without departing from the invention.Accordingly, the drawings and description are to be regarded asillustrative in nature, and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference is made to the attached drawings, wherein elements having thesame reference numeral designations represent like elements throughout,and wherein:

FIG. 1 is a block diagram of a sensing surgical instrument systemaccording to an embodiment of the present invention.

FIG. 2a shows a right angle surgical stapler according to an embodimentof the present invention.

FIG. 2b shows a linear surgical stapler according to an embodiment ofthe present invention.

FIG. 2c shows a circular surgical stapler according to an embodiment ofthe present invention.

FIG. 3a shows sensing elements situated on a staple side outside of thestaple lines of a surgical stapler according to an embodiment of thepresent invention.

FIG. 3b shows sensing elements situated in a sleeve fixed to a staplerhead of a surgical stapler according to an embodiment of the presentinvention.

FIG. 3c shows sensing elements interleaved with staples in a surgicalstapler according to an embodiment of the present invention.

FIGS. 4a-4e show fiber configurations of an optical sensor tip accordingto embodiments of the present invention.

FIG. 5a is a block diagram of a configuration for transmitting light forthe optical sensor of FIGS. 4a -4 e.

FIG. 5b is a block diagram of a configuration for receiving light forthe optical sensor of FIGS. 4a -4 e.

FIG. 6a is a graph showing the relationship between light absorption andincident wavelength for varying tissue oxygen saturation.

FIG. 6b is a graph showing an example of light absorption in tissueduring de-oxygenation and re-oxygenation.

FIG. 6c is a timing diagram for an oximetry-type algorithm according toan embodiment of the present invention.

FIG. 7 is a flowchart for oximetry-type oxygenation sensing according toan embodiment of the present invention.

FIG. 8a is a graph showing a response to incident light and fluorescedlight as fluorescent dye is introduced into a living tissue.

FIG. 8b shows a simulated representative fluorescent sensor response asthe sensor traverses perfused and non-perfused tissue according to anembodiment of the present invention.

FIG. 9 is a flowchart for fluorescence sensing according to anembodiment of the present invention.

FIG. 10a illustrates a system according to an embodiment of the presentinvention with light sources and receivers external to an instrument.

FIG. 10b illustrates a system according to an embodiment of the presentinvention with light sources, light receivers, and light guides internalto an instrument.

FIG. 10c illustrates a system according to an embodiment of the presentinvention with micro fabricated internal light sources, light receivers,and light guides.

FIG. 11a illustrates a sensor configuration according to an embodimentof the present invention where sensing elements are situated on aflexible substrate.

FIG. 11b illustrates a sensor configuration on a surgical retractor foropen surgery according to an embodiment of the present invention.

FIG. 11c illustrates a sensor configuration on a grasper for minimallyinvasive, laparoscopic surgery according to an embodiment of the presentinvention.

FIG. 11d illustrates a sensor configuration where sensors are implantedinto the body and transmit data wirelessly according to an embodiment ofthe present invention.

FIG. 11e illustrates a remotely powered integrated sensor and wirelesstransmitter according to an embodiment of the present invention.

FIG. 12a shows a surgical staple or clip with sensing capabilitiesaccording to an embodiment of the present invention.

FIG. 12b is a cross-sectional view the sensing staple or clip of FIG. 12a.

FIG. 13a illustrates a system according to an embodiment of the presentinvention where the staples or clips measure electrical impedance.

FIG. 13b illustrates a system according to an embodiment of the presentinvention where staples or clips and a reference sensor perform electricelectrical stimulation and electrical activity sensing.

FIG. 14 is a block diagram of an intelligent expert system according toan embodiment of the present invention with integrated sensing,monitoring, data storage, outcome prediction, and display capabilities.

DESCRIPTION OF THE INVENTION

Conventional surgical instruments having sensors for measuring tissueproperties have no means of adapting to patient-specific characteristicsthat are of utmost importance in avoiding surgical procedure failure.The present invention addresses and solves these problems stemming fromconventional sensing surgical instruments.

According to the present invention, a system provides expert proceduralguidance based upon patient specific data gained from surgicalinstruments incorporating sensors on the instrument's working surface,one or more reference sensors placed about the patient, sensorsimplanted before, during or after the procedure, the patient's personalmedical history, and patient status monitoring equipment. In certainembodiments, the system records data across the entire patient encounterincluding pre-operative, intra-operative and post-operative periods, aswell as immediate, acute, short term, and long term outcomes bothlocally in hospital-based units as well as remotely in a datarepository.

In other embodiments, the inventive system generates patient-specificexpert guidance in optimizing surgical procedures based uponstatistically matched data from a central repository, and/or adapts itsguidance based on continuously updated, statistically significant data.

The present invention will now be described in detail with reference toFIGS. 1-14.

FIG. 1 schematically shows a representative sensing surgical instrumentsystem with adaptively updating algorithms according to an embodiment ofthe present invention. This embodiment specifically depicts a sensingsurgical stapler 101 for measuring properties of tissue 102. One or moreother similarly instrumented well-known surgical instruments including,but not limited to, clip appliers, graspers, retractors, scalpels,forceps, electrocautery tools, scissors, clamps, needles, catheters,trochars, laparoscopic tools, open surgical tools and roboticinstruments may be integrated into the system instead of or in additionto stapler 101. Sensing elements 104 reside on the stapling element side105 and/or the anvil side 106. The stapler is coupled via a conventionaloptical, electrical, or wireless connection 108 to a processing andcontrol unit 120.

The system of FIG. 1 includes one or more reference measurement points,internal or external, invasive, minimally invasive or noninvasive,intracorporeal or extracorporeal. One example of such a referencemeasurement sensor, shown in the form of a clip 110, grasps referencetissue 112, typically healthy tissue in the same patient serving as areference for use as a patient-specific baseline measurement. Sensingelements 111 are on one or both sides of the jaws 116 and 117. Referencesensor 110 need not be a clip, but can be a probe or any other sensinginstrument or device. Reference sensor 110 is coupled via a conventionaloptical, electrical, or wireless connection 118 to processing andcontrol unit 120.

In certain embodiments of the inventive system of FIG. 1, opticalsignals are generated by the sensor controller 123, light returning fromthe distal end of the sensors is received by sensing unit 121, and theassociated signals are conditioned in signal processor 122 and convertedinto a dataset, which is stored in a memory, such as database 131. Aprocessor 124, is coupled to both the input and output datasets andcompares the information to determine characteristics of the tissue, thepatient, and the procedure. The processor 124 comprises, for example, aconventional personal computer or an embedded microcontroller ormicroprocessor. Control and monitoring of the sensor outputs 123 andinputs 121 respectively is performed with conventional commerciallyavailable or custom-made data acquisition hardware that is controlled bythe processor 124. Signal processor 122 is integral with processor 124,or is a conventional digital or analog signal processor placed betweenthe sensor input 121 and the processor 124. Depending on the sensingmodality, the sensor data is translated into information that relates totissue properties. In one exemplary optical sensing embodiment,oximetry-type techniques are used to convert the relative absorption ofdifferent wavelengths of light into an oxygen saturation percentage ofhemoglobin in the blood. In another optical sensing modality,fluorescence response due to a fluorescent medium that has beenintroduced into the body is measured, and characteristics of theresponse including the intensity rise time and steady state value areindicative of the blood flow in the tissue in question. All raw data andprocessed results are recorded by a recorder 130. This dataset caninclude measurements made preoperatively, intra operatively, and/or postoperatively, as well as pre procedurally (before actuation of thedevice), at the time of the procedure (as the device is actuated),and/or post procedurally (immediately and delayed after actuation of thedevice). In addition, outcomes are recorded; these outcomes includeimmediate outcomes (during procedure), acute outcomes (within 24 hours),short term outcomes (within 30 days), and long term outcomes. Postprocedure outcomes can be either quantitative measurements fromimplantable or other sensors, lab results, follow up imaging or othersources, or they can be qualitative assessments of the patient and theprocedure by a medical professional.

A dynamically updated database of past patient encounters 131 is coupledwith the processor 124 for creating a decision about tissue health basedon previous knowledge. Database 131 includes information about thecurrent patient and also data from previous patients that is used tomake an informed decision about the tissue health and the likelihood ofsuccess of a procedure. The system offers solutions to the medical teamto optimize the chance of procedural success. The collected datasetincluding sensor data and outcomes from the current procedure are addedto database 131 to help make more informed future decisions. Outcomescan be added, after follow up visits with the patient at a later date,into either the system or a external database from an external source.The database 131 may be stored locally in base unit 120 or externally,but is updated by and sends updates to a central database that servesother base units 120 via a communications device 138, such as aconventional modem, an internet connection, or other network connection.Further, recorder 130 can be linked to a central repository for patientinformation to include some or all recorded information with medicalhistory in patient records.

Large amounts of data are collected for each patient. The database 131contains all of the collected information and the correspondingoutcomes, or a statistically significant subset of the collected dataand patient outcomes. The database, or a subset thereof, acts as astatistical atlas of predicted outcomes for a given set of sensorinputs. Conventional techniques are used for determining therelationship between the current sensor readings and those of the atlas,to interpolate or extrapolate a predicted outcome or likelihood ofprocedure success or failure. One technique well-known in the artrepresents the current patient's sensor and other inputs in a vector;the similar datasets from the atlas or database are represented in asimilar form as a set of vectors. The “distance” between the currentpatient data and each set of previously stored data is determined;distance can be determined as the standard Euclidean distance betweenthe vectors; i.e. the 2-norm of the difference between the vectors, orother distance measures as known in the art including other norms andthe Mahalanobis distance. The difference between the vectors, or thevectors themselves, can be multiplied by a weighting matrix to take intoaccount the differences in the significance of certain variables andsensor readings in determining the outcome. The set of distances of thecurrent dataset from the previously stored sets is used as a weightingfactor for interpolating or extrapolating the outcome, likelihood ofsuccess or failure, or other characteristics of the previously storeddatasets. In another well-known technique, methods typically used inimage processing and statistical shape modeling for deforming astatistical atlas can be incorporated. A base dataset generated from thedatabase of previously collected datasets and the most statisticallysignificant modes of deformation are determined, where the previouslycollected datasets act as training datasets. The magnitudes of thedeformation for each mode are determined to best match the atlas modelto the current dataset. The magnitudes are then used to deform the setof previous outcomes in a similar fashion, or otherwise interpolatebetween the previous outcomes by determining how the each outcome isdependent on each mode of deformation, to determine the best fit for thecurrent patient. Other conventional techniques for predicting outcomesbased on prior and current datasets are based on determining thesimilarity between the current dataset with those that were previouslyacquired from other patients, and using the similarity measure todetermine a likelihood of a given outcome responsive to thosecorresponding to the prior datasets.

Attached to, or integrated directly into, the base control unit 120 isone or more output devices 134. Output device 134 is used to providepersons performing the procedure information about the physiologiccondition of the tissue, and to help guide the procedure. The outputdevice 134 takes information from the sensors, prior data, patientrecords, other equipment, calculations and assessments, and otherinformation and presents it to the clinician and operating room staff ina useful manner. In one embodiment, the measured information is comparedwith prior datasets and prior patient outcomes, and the output devicedisplays information to help assess the likelihood of success of a givenprocedure with the current configuration. The information displayed cansimply be a message such as “go ahead as planned” or “choose anothersite.” In another embodiment, the information is encoded in some form ofsensory substitution where feedback is provided via forms including, butnot limited to, visual, audible, or tactile sensation.

FIGS. 2a-2c depict specific stapler configurations according toembodiments of the present invention. FIG. 2a depicts a right anglesurgical stapler 201. The stapling element side of the jaws 202 isinstrumented with sensing elements 204 and 206 associated with each setof staple lines 208 and 210 which are on both sides of the cutter 212.In this embodiment, the anvil side of the jaws 214 is not instrumentedwith sensors. Sensing elements 204 and 206 can be placed on either orboth sides of the jaws 202 and 214. In one embodiment, the stapler iscoupled via optical cable 220 to the previously described processing andcontrol unit 120. This coupling 220 can also be electrical or wireless.

FIG. 2b depicts a linear surgical stapler 231 according to an embodimentof the present invention. The stapling element side of the jaws 232 isinstrumented with sensing elements 234 and 236 associated with each setof staple lines 238 and 240 which are on both sides of the cutter 212.In this embodiment, the anvil side of the jaws 214 is not instrumentedwith sensors. Sensing elements 204 and 206 can be placed on either orboth sides of the jaws 232 and 234. The stapler is coupled via opticalcable 250 to the previously described processing and control unit 120.This coupling 250 is electrical or wireless.

FIG. 2c depicts a circular surgical stapler 261 according to anembodiment of the present invention. The stapling element side of thejaws 262 is instrumented with a ring of sensing elements 264 associatedthe ring of staples lines 270 and outside of the circular cutter 272.Since the anvil is detachable and connected by pin 278, in thisembodiment, the anvil side of the stapler 276 is not instrumented withsensors. Sensing elements 264 are placed on either or both the staplingelement side 264 and the anvil side 276. The stapler is coupled viaoptical cable 280 to the previously described processing and controlunit 120. Alternatively, this coupling 280 is electrical or wireless.Other stapler designs or clip appliers are instrumented similarly, withone or more sensors on one or both sides of the jaws.

FIGS. 3a-3c show configurations of sensing elements on the surface of alinear stapler according to embodiments of the present invention. Theseconfigurations are generalized to any shaped stapler or other surgicalinstrument. Sensing elements are shown in a linear arrangement; they canbe arranged in other patterns including staggered rows, randomized,single sensors and arrays of sensors. FIG. 3a shows a linear staplerhead 301 with sensing elements 306 and 308 on the outside of staple orclips 303 and 304, which are outside the cutter 302. Cutter 302 isoptional, and there may be a total of one or more staples, staple lines,or clips. The sensing elements 306 and 308 are situated such that theysense the tissue outside of the staple lines on one or both sides.

FIG. 3b shows a linear stapler head 321 according to an embodiment ofthe present invention. Attached to the stapler or integrated intostapler head 321 is a strip or shell 327 and 329. This shell can bepermanently integrated into the stapler or an addition to the stapler.Thus, it can be a modification to an existing stapler. Enclosed in thesensing shell 327, 329 are sensing elements 326 and 328. The staplercomprises one or more staples or clips 323 and 324 and cutters 322.

FIG. 3c shows a linear stapler head 341 with the sensing elements 346and 348 integrated into the stapler head, according to an embodiment ofthe present invention. The sensing elements are placed such that theyare in line with or integrated between the staples or clips 343, 344.Medial to the staples and sensors is an optional cutter 342. The sensorsare placed on one or both sides of the cutter.

FIGS. 4a-4e show configurations of optical sensing elements according toembodiments of the present invention where a surgical instrument iscoupled to base unit 120 optically. This coupling can also be electricalor wireless with the actual electronic sensing elements placed in theinstrument as opposed to an optical coupling from a remote source.

FIG. 4a shows an embodiment where the sensing element contains fouroptical fibers 405, 406, 408, and 409. These are embedded in a medium402, typically optical epoxy, and enclosed in sheath or ferrule 401. Inthis embodiment, two optical fibers are used to transmit light into thetissue and two others are used to return light to the receiver in thebase unit 120. The arrangement of the emitting and receiving elements issuch that matching emitter/receiver pairs are adjacent or opposing.Further, the same optical fiber can be used to transmit light in bothdirections. One or more optical fibers are used to transmit light to andfrom the working surface of the instrument.

FIG. 4b shows an optical fiber arrangement with fibers 425, 426, and 428embedded in a medium 422 which is enclosed in a sheath or ferrule 421.In this embodiment of the invention, two optical fibers are used fortransmitting light into the tissue and a single fiber is used to returnlight to the receiver. FIG. 4c shows a similar embodiment where thereare two optical fibers 446 and 448 embedded in medium 442 inside ofsheath or ferrule 441. In this embodiment, a single optical fibertransmits all light to the tissue and a single fiber receives light fromthe tissue.

FIG. 4d shows an embodiment where there is a ring of optical fibers 466that surround optical fiber 464 inside of medium 462 enclosed in sheathor ferrule 461. The outer ring of fibers 466 is used to transmit lightwhile the inner fiber 464 receives light. Alternatively, the outer ringof fibers 466 can be used to receive light transmitted from the innerfiber 464.

FIG. 4e shows another embodiment of the sensing element which contains amultitude of optical fibers 484 stabilized in a medium 482 enclosed in asheath or ferrule 481. The fibers are arranged in an arbitrary or randompattern of light emitters and light receivers. Each fiber is attached toan individual light source or light sensor, and/or more than one fiberis coupled optically to share a light emitter or sensor.

FIG. 5a schematically displays a configuration of the light emittingcomponents for a single measurement point in one embodiment of thesensing stapler or other sensing instrument of the invention. Aprocessor 501, contained in the base unit 120 or onboard the instrument,commands the light controller 502, which also is located either in thebase unit 120 or onboard the instrument. The light controller 502 iscoupled to the light sources for one sensing modality by connections504. The light sources 506, 508, and 510 provide the light that isincident on the tissue 102. In one embodiment, these light sources arelasers with wavelengths centered at red (near 660 nm), near-infrared(near 790 nm), and infrared (near 880 nm), respectively. Thisconfiguration is used for oximetry-type sensing where one wavelength issituated at the isobestic point for light absorption in hemoglobin, oneis situated at a greater wavelength, and one is situated at a lesserwavelength. Light sources 506, 508, and 510 are one, two, three, or moredistinct light emitters and are laser, light emitting diode (LED), orother sources. Alternatively, these distinct light sources are abroadband light source such as a white light. If more than one lightsource is used, optical couplings 514 connect the sources to a lightcombiner 516. If more than one output is required (i.e. more than onemeasurement point using the same light source), optical coupling 518takes the light into a light splitter 520. Optical couplings 524 takethe light to the appropriate fiber assembly 530. Light is transmittedout of the fiber assembly at the fiber end 532 on the tip. This tip isas depicted in FIG. 4 a.

The light controller 502 controls the light emitter for one or moresensing modalities. In this embodiment, there are two optical sensingmodalities: oximetry-type tissue oxygenation sensing and fluorescencesensing. Coupling 536 allows the light controller to control lightsource 538. Light source 538 is a high power blue LED with a centerwavelength of 570 nm. This light emitter is a laser, LED, or other lightsource. This source is composed of one or more sources that emit lightat one or more wavelengths or a broadband light source emitting at aspectrum of wavelengths. Optical filtering can also be performed on abroadband light source to produce the desired spectral output. The lightfrom light source 538 is coupled optically 540 to a light splitter 542if more than one measurement point uses the same source. Opticalcoupling 544 connects the light to the optical cable assembly 530, andlight is emitted at tip 548.

In another embodiment of the invention, the light from optical fibers524 and 544 is combined and the light is emitted from an optical fiberassembly as described in FIG. 4b, 4c , or 4 d (emitter as fiber 464). Ina further embodiment, the light from optical fibers 524 and 544 issplit, or combined and split, into multiple fibers to be used with acable assembly as shown in FIG. 4d (emitters as fibers 466) or FIG. 4 e.

FIG. 5b schematically displays a configuration of light receivingcomponents for a single measurement point in one embodiment of thesensing stapler or other sensing instrument 101. Light from the emitterdescribed in FIG. 5a is incident upon the tissue being queried and thetransmitted and/or reflected light passes into the tip 552 and returnsthrough the optical cable assembly 530. Optical coupling 554 directs thelight to light sensors 556. In one embodiment, light sensor 556 is anavalanche photodiode. Sensor 556 is, but is not limited to, conventionalphotodiodes, avalanche photodiodes, CCDs, linear CCD arrays, 2D CCDarrays, CMOS sensors, photomultipliers tubes, cameras, or other lightsensing devices. In a further embodiment, light sensor 556 is aspectrometer or equivalent device that measures light intensity at oneor more discrete wavelengths. In a still further embodiment, lightsensor 556 is a set of selective photodiodes tuned to the wavelengths ofemitted light from light sources 506, 508, and 510. Selectivephotodiodes are either naturally tuned to specific wavelengths orcoupled with an appropriate optical filter. Light sensors 556 arecoupled 558 with a signal processor 560. The signal processor 560performs filtering, demodulating, frequency analysis, timing, and/orgain adjustment, and/or other signal processing tasks. The signalprocessor 560 is coupled with the processor 501 where furthercalculations, analysis, logging, statistical analysis, comparisons withreference, comparisons with database, visualization, notification,and/or other tasks are performed or directed.

Light from the emitter described in FIG. 5a is incident upon the tissuebeing queried and the transmitted and/or reflected light also passesinto the tip 564 and returns through the optical cable assembly 530.Light is directed via optical coupling 568 to optical filters 572. Inthe fluorescence sensing modality, the optical filter 568 is a band passor other filter that blocks the incident, excitation light whileallowing the fluoresced light to pass. Filter 572 is also useful toblock the emitted light from other sensing modalities and/or other lightincluding ambient light. The filter light is coupled optically viacoupling 574 to light sensors 578. In one embodiment, light sensor 578is an avalanche photodiode. In other embodiments, light sensor 578 isthe same form as light sensors 556. Light sensors 578 are coupled 580with the signal processor 560 which is in tern coupled with theprocessor 501. The processor 501 and signal processor 560 perform thesame functions as described previously with reference to FIG. 5 a.

FIGS. 6a and 6b show plots that are used to describe oximetry sensingmodality. FIG. 6a shows the relationship between light absorption 601and light wavelength 602 for a range of tissue oxygenation levels 603.The vertical lines 620, 624 and 628 correspond to the wavelengths of 660nm, 790 nm and 880 nm respectively. The light absorption 601 for therange of oxygen saturation levels 603 is different for each of thewavelengths. As oxygen saturation 603 decreases, the absorptionincreases for red light 620 and decreases for near-infrared light 628.At the isobestic wavelength near 624, light absorption is invariant tooxygen saturation. This wavelength can be used for calibration and fornormalization of the signal to allow for consistent readings regardlessof optical density of the tissue. One embodiment of the oxygen sensingmodality emits light at the isobestic wavelength, one wavelength greaterthan the isobestic and one wavelength less than the isobestic, andsenses the absorption responsive to the measured response. Otherembodiments emit one or more wavelengths of light and measure thetransmitted, reflected, or otherwise measurable light to determine theabsorption, slope of the absorption function, or other characteristicsof the response that can be related to the blood oxygen saturation andtissue health.

FIG. 6b shows a plot that represents an experiment used to verify therelationship between oxygen saturation and light absorption. Red lightat 660 nm represented by 652 and near infrared light at 880 nmrepresented by 654 are used to illuminate a section of tissue. At thetime marked by 658, blood supply to the tissue is occluded. At the timemarked by 660, the blood supply is restored. As blood supply isrestricted and tissue oxygen saturation drops, the transmitted lightintensity (inverse of absorption) increase for near infrared light 620and decreases for red light 654.

FIG. 6c shows a timing diagram and representative response for analgorithm according to the present invention used for oximetry-typeoxygen saturation level sensing. The algorithm provides for a robustmethod of sensing oxygenation that results in a response that isminimally responsive to tissue type, color, thickness, or otherproperties. The timing diagram in FIG. 6c presents the method when twowavelengths of light (red and infrared) are used. It is extendable toother numbers of sources, and other types of sources and sensors.

The diagram of FIG. 6c shows the output light intensity 670 and theresponsive light received 672 with respect to time 674 over a timeperiod or cycle length 676. In one embodiment, the light emitter is abi-color, bi-polar LED that emits red (660 nm) and infrared (880 nm)light; when a positive voltage 678 is applied, infrared light isemitted, and when a negative voltage 680 is applied, red light isemitted.

The light output intensities and corresponding response intensities aredenoted with letters in the following description for use in theequations hereinbelow. In each cycle 676, red light is emitted withintensity 678 (A) and the corresponding sensed light intensity 678 (F)is recorded. Light is then shut off 682 (B) and the correspondingreceived light intensity 684 (G) is recorded as a baseline. Infraredlight is emitted with intensity magnitude 686 (C) and the correspondingsensed light intensity 688 (H) is recorded. To make the tissue responsemore invariant to tissue properties other than oxygenation (i.e. tissueoptical density and thickness), the maximum intensities where light canno longer sufficiently pass through (or other transmission method) thetissue and return to the sensor. Light intensity is ramped from 686 to682. At time 690, the signal is lost and the output intensity 692 (D) isrecorded. Light intensity is ramped from 682 to 678. At time 694, thesignal is regained and the output intensity 696 (E) is recorded. Thetimes 690 and 694 and corresponding intensities 692 and 696 aredetermined by a simple threshold on received intensity 672.

In another embodiment, these levels are determined by placing athreshold on a moving average, integration, derivatives, curve fitting,or other methods. Described is one embodiment of the timing for a robustoxygenation-type algorithm. Other functionally identical or similarembodiments exist.

A measure related to tissue oxygenation can be calculated responsive tothe output and corresponding receiver light intensities. Initially, the“red ratio” is defined and is evaluated as (H−G)/(C−D), and the“infrared ratio” is defined and is evaluated as (F−G)/(A−E), where theletters correspond to the magnitudes of the light intensities asdescribed. The numerator of the ratios determines the response aftereliminating effects of ambient or other external light sources. Thedenominator of the ratios normalizes the response by the amount of lightthat was actually incident on the tissue that made it back to thesensor. The oxygenation is responsive to the two ratios. The “relativeoxygen saturation” is defined as the red ratio divided by the infraredratio and is related, not necessarily linearly, to the oxygen saturationof the tissue being measured. The relative oxygen saturation is usefulfor determining trends in oxygenation and also as a comparison withrespect to time and/or a separate reference sensor. One importantdifference between the technique described and that of standard pulseoximetry is that the employed algorithms are not based on pulsatile flowin the tissue. Therefore, it is possible to acquire the tissue oxygensaturation even if blood flow is non-pulsatile, or even not flowing.Further, the algorithms incorporated improve measurement robustness andstability by compensating for tissue thickness and type (or morespecifically, the optical impedance of the tissue being measured).

FIG. 7 is a flowchart for one inventive embodiment of the oxygen sensingmodality based on oximetry. This embodiment uses oximetry-typetechniques for determining the light response from tissue responsive tothree excitation wavelengths. These three wavelengths can include thosedescribed earlier: one red light source, one infrared light source, andone light source at the isobestic wavelength. The measured response inthe absence of an excitation light is used as a baseline intensity andsubtracted from the three measured responses. All raw data is logged,and a calculation is performed to convert the light absorption for thethree wavelengths to a value related to tissue oxygenation. Thecalculated values are compared to a database or other previouslyacquired or determined dataset. Although exactly three wavelengths areshown, other embodiments use one or more wavelengths of excitationlight. In further embodiments, the intensities for each of theexcitation lights may be ramped in intensity as detailed in FIG. 6c tocreate a more robust measurement that is invariant to tissue opticaldensity.

FIGS. 8a-8b show typical results for experiments with the fluorescentsensing modality. Tissue perfusion can be assessed using fluorescence.Biofluorescence can be achieved using a variety of commerciallyavailable products. One example is fluorescein isothiocyanate which isan intravenously injected, biocompatible dye which fluorescesyellow-green (peak near 520 nm) when illuminated with anblue/ultraviolet (peak near 488 nm) source. This sensing modality can beincorporated into the configurations shown to allow for multi-modalitysensing, or included as a stand-alone sensor. A dense array of sensorsenables imaging of the perfusion along a line and a determination ifthere are patches of poorly perfused tissue in an otherwise healthyregion. Stapler fluorography can also utilize fluorescent microspheresand quantum dots. These entities can be used as molecular tracers tocharacterize tissue substructure such as vessels, or bile ducts. Inaddition, inflammatory mediators and other biomolecules germane toanastomosis viability can be detected though fluorography at a stapleline.

FIG. 8a represents the measured intensity of the transmitted and/orreflected incident light 808 and the measured intensity of thefluoresced response 804 to the incident light source. The plot shows thelight intensity centered at the incident and fluoresced wavelengths asfluorescent dye is instilled into or perfused though the bloodstream attime 812. As the dye perfuses into the tissue being measured, thefluorescent response becomes evident and the sensed incident lightdecreases. The slope, rise time, magnitude, steady state value, shape,integral, or other characteristics and curve properties of the onset offluorescence 816 can be used to determine characteristics of the tissueperfusion and health. The steady state values of the fluoresced light824 and incident light 828 can be used to determine tissue perfusion andoverall health and/or the type of tissue. The measured response can beused alone, with a previously collected dataset from the same or otherpatients, or in conjunction with a reference signal. Infusion of thefluorescent medium can be introduced either in a single injection, or itcan be ramped up in either continuously or in discrete increments. Byvarying the amount of fluorescent medium introduced into the patient,continuous or multiple measurements can be performed of thecharacteristics of the onset of fluorescent response.

FIG. 8b shows typical results for passing a fluorescence sensing probe850 across a tissue sample 852. In one case, the fluoresced response 858serves as a baseline for healthy tissue 856 and the decreased intensity862 corresponds to a region of tissue that is depleted of blood supply860. Alternately, the baseline intensity can be the lower level 862 andthe fluorescence peaks to 858 as the probe passes over a blood vessel860. This scanning technique can be used to determine sections of tissuewith proper perfusion. In one embodiment, multiple sensor probes 850 areintegrated in a linear, grid like, or other arrangement on the surfaceof a surgical instrument such as a stapler, a retractor, a grasper, aclip applier, a probe, a scope, a needle, a catheter, a mesh substrate,or other device.

FIG. 9 is a flowchart for one embodiment of the inventive fluorescencesensing modality. Light containing or centered at a wavelength thatexcites the fluorescent medium is transmitted into the tissue. The lightintensity of the fluorescent response is then measured; optical filters,wavelength selective light receivers, or a spectrometer are used todifferentiate excitation light and fluorescent response. The measuredresponse in the absence of an excitation light is used as a baselineintensity and subtracted from the fluorescent response. All raw data islogged, and a calculation is performed to determine one or moreproperties of the onset of the fluorescent response and the steady statevalue as described earlier. The calculated values are compared to adatabase or other previously acquired or determined dataset. Thissensing modality can be combined with that described by the flowchart ofFIG. 7. In one embodiment, both oximetry-type sensing as represented inFIG. 6 and FIG. 7 and fluorescence-type sensing as represented in FIG. 8and FIG. 9 are combined into a single integrated device. The schematicdiagram shown in FIG. 5 shows how light sources and detectors for bothsensing modalities can be integrated into a single system. Other sensingmodalities, optical or other types, can be combined to performmulti-modality sensing on the working surface of surgical instruments.

FIGS. 10a-10c present techniques that can be used to perform saidoximetry-type and/or fluorescence-type sensing. These techniques can becombined with other sensing modalities including optical sensors,electrical sensors, chemical sensors, mechanical sensors, MEMS sensors,nano sensors, biochemical sensors, acoustic sensors, immunologicsensors, fluidic sensors, or other types of sensors.

FIG. 10a shows a surgical stapler embodiment of the system configurationwhere all light sources and detectors are located external of thesurgical instrument's body. In this embodiment, the light sources anddetectors are located in control unit 1001 and sensing, control,calculations, and communications are performed in control electronics1003. In one embodiment, control unit 1001 constitutes durable equipmentand instrument 1028 is a potentially disposable device. For eachmeasurement point, one or more light sources 1005 are coupled opticallyvia 1007 to a light combiner 1009. The light sources can be narrowbandemitters such as LEDs and lasers and/or broadband light sources such aswhite lights and can be use with or without additional opticalfiltering. For the same measurement point, one or more light receivers1001 are coupled optically via 1013. The light receivers can bephotodiodes, photodiode arrays, avalanche photodiodes, photomultipliertubes, linear and two dimensional CCDs, CMOS sensors, spectrometers, orother sensor types. The light traveling through couplers 1009 andreceiver couplings 1013 are coupled to an optical connector 1020. In oneembodiment, this connector is a standard high density fiber opticconnection and coupling 1022 is a standard high density fiber opticcable. Coupling 1022 connects to the sensing instrument 1028 atconnector 1024 and passes through fiber 1030 to a breakout 1032. Sensorpoints 1034 can be either single fibers or multi-fiber sensor tips asrepresented in FIGS. 4a-e . The sensor tips transmit the incident lightonto tissue 1036 and/or receive the reflected, transmitted, and/orfluoresced light from said tissue.

FIG. 10b depicts an embodiment where the light emitting and receivingcomponents are located onboard a surgical instrument. In thisembodiment, circuit board 1051 is mounted in or on the instrument andcoupled via 1053 to a control unit. Coupling 1053 is electrical, opticalor wireless. Attached to circuit board 1051 are light sources 1057 andlight receivers 1060. In one embodiment, they are standard surface mountLEDs and photodiodes. Light guides, light combiners, and/or lightsplitters 1064 direct light to and from the sensing working surface 1066of the instrument to and from the tissue being monitored 1068. In oneembodiment, 1051 represents a flexible medium and light sources andreceivers 1057 and 1060 represent alternative light sources and emitterssuch as organic LEDs and organic photo detectors.

FIG. 10c shows a further embodiment where the light emitting andreceiving components are located onboard a surgical instrument. In thisembodiment, the electronics are microfabricated into a compact sensingelement that can fit onto the working surface of the instrument. Asdescribed hereinabove, coupling 1083 connects the circuit to an externalcontroller. The circuit is built on base 1081. Light emitters 1087 anddetectors 1090 are embedded in layer 1092. Coupled to the light sourcesand detectors are micro fabricated light guides, light combiners, and/orlight splitters 1094 in layer 1096. The light guides direct light to andfrom the tissue being monitored 1098.

FIGS. 11a-11c depict further embodiments of sensing surgical instrumentsand devices according to the present invention. FIG. 11a shows a sensingflexible mesh 1104 that contains sensing elements 1106. Sensing elements1106 can be electrical, optical, chemical, or other sensor types used tomonitor the tissue 1102 or other operational parameters. The mesh 1104can mold to the surface of tissue 1102. In one embodiment, sensors 1106are oxygenation sensors as described previously and are used to monitorthe tissue health and other tissue properties. In addition, when thereis a plethora of sensors, mapping of the oxygenation levels of thesurface of the tissue 1102 can be performed. If the location of thesensors is known with respect to the tissue or imaging device, then thismapping can be overlaid on medical imaging information including x-ray,computed tomography, magnetic resonance imaging or ultrasound images andvolumes, or it can be overlaid on a video signal from an endoscope orother camera. In another embodiment, sensors 1104 are electrical sensorsthat are used for EMG or other electrical activity or impedance mapping.The mesh is coupled via 1108. Coupling 1108 is electrical, optical, orwireless. Sensors 1104, in optical sensing modalities, are eitheronboard electronics or the distal tips of optically coupled emitters anddetectors.

The sensing surgical mesh can be generally described as a rigid orflexible surface that contains sensing elements. The sensing elementsdetect information about the tissue upon which they are placed. The meshis flexible, or preshaped to conform to the tissue being monitored. Inone embodiment wherein the mesh is bioabsorbable, the mesh is made ofbioabsorbable polymers similar to those used in conventional absorbablesutures. In another embodiment wherein the mesh is durable, the mesh ismade of polymers similar to those used in conventional non-absorbablesutures. In a further embodiment, the substrate is an adhesion barriermaterial, such as Seprafilm®, available from Genzyme Corp. of Cambridge,Mass. The tissue being monitored is either internal tissue, such as anorgan being monitored after transplant or a bowel segment whoseperfusion is to be verified, or is external tissue, such as a skin flapbeing monitored for reconstructive surgery, or skin being monitored forthe prevention of bed sores. The mesh sensor array is either a temporarydevice used during a procedure (either single use or reusable),permanently implantable, or of a bio degradable, bio absorbable natureas is known in the art.

FIG. 11b shows a surgical retractor 1122. The working surface of theretractor 1124 is instrumented with sensors as previously described(i.e., with sensing elements 1106) for measuring properties of a tissue1128. In addition to monitoring tissue properties, interactions withtissue 1128 are measured using strain gages, piezoelectric sensors, loadcells, multi-axis force/torque sensors, and/or other sensors 1130 and1132. The retractor handle 1134 is held manually by a member of theoperating room staff, mounted to a: frame or passive arm, or held by arobotic retraction system. Coupling 1136 couples sensors 1126, 1120,and/or 1132 to an onboard or external control interface (not shown) asdescribed hereinabove. In one embodiment, sensors 1126 are oximetry-typesensors comprising of a plethora of multi-color LEDs and photodiodes andsensors 1130 and 1132 are either strain gages or multi-axis force/torquesensors respectively for measuring the forces incident upon the tissueduring retraction while simultaneously monitoring oxygenation levels. Inthe case of a robotic retraction system or other robotic-assistedsurgery scenario, the sensed information including interaction forcesand tissue status is used to close the control loop for the robot and/orprovide warnings or augment the motions of the robot manipulator.

FIG. 11c displays a surgical grasper that is instrumented with sensors1144 mounted on grasper jaws 1146 and 1148. The grasper clamps orotherwise contacts tissue 1142 and senses oxygenation, tissue perfusion,electrical properties, chemical properties, temperature, interactionforces, grasping forces, and/or other parameters. Coupling 1152 couplessensors 1144 to an onboard or external control interface (not shown) asdescribed hereinabove. Sensors 1144 can be placed on one or both sidesof the jaw and/or on the shaft 1150 of the instrument. In oneembodiment, the grasper measures the oxygenation level of the tissuebeing grasped while simultaneously monitoring grasping force and othertissue interaction forces.

FIG. 11d shows a configuration for a sensor implanted in the body thatrelays information back to a controller. Sensor device 1160 contains oneor more sensing elements 1162. The sensing elements can be any of thetype described earlier including oxygenation, fluorescence, tissueperfusion, general health, tissue electrical impedance, tissueelectrical activity, interaction forces, pH, electromyography,temperature, spectroscopy, fluid flow rate, fluid flow volume, pressure,biomarkers, radiotracers, immunologic, chemical, nerve activity, andevoked potential, and other sensor types capable of determiningcharacteristics of tissue. The sensor device 1160 is placed inside of,on the surface of, embedded into, or wrapped around tissue 1164. Thetissue being monitored is, for example, an organ, a bowel segment, ablood vessel, a chest wall, or other biological tissue. The sensor canbe temporary, permanently implantable, or bioabsorbable/biodegradableinside of body 1166. In one embodiment, the sensor device is implantedonto the bowel and used for monitoring the tissue after a procedure andfor obtaining data related to short and long term outcomes. In anotherembodiment, the sensor is a ring that is placed around a blood vesseland is used to monitor blood flow in said vessel.

In some embodiments, one or more sensor devices on one or more tissues1164 are communicatively coupled via 1170 to a communications interface1172. In one embodiment, the coupling 1170 is a wireless link where thepower from a radio frequency signal generated by 1172 powers the sensordevice 1160 which then takes a measurement and return data via wirelesscoupling 1170. The communication interface is coupled via 1174 to a maincontrol unit 1176. In another embodiment, the communications interface1172 is a portable battery powered device that can be carried by thepatient, or a fixed device placed inside or outside of a hospital or amedical professional's office for powering and monitoring the internalsensors 1160. The communication interface 1172 can conveniently obtainacute, short, and long term follow-up data about a procedure after thesurgery is complete. The communications interface 1172 and controller1176 may be one in the same. In one embodiment, the controller 1176 isthe main system's base control unit 120. In another embodiment, thecommunication interface 1172 is directly in communication with the mainsystem's base unit 120 or the central database 131 directly.

In a further embodiment of the system shown in FIG. 11d , the sensordevice contains a MEMS sensing element and communications electronics,is placed in or on internal tissue, and communicates wirelessly with andreceives power from an external radio frequency source for the purposeof post procedure patent monitoring. In another embodiment, the sensingelement is made of biocompatible materials known in the art, and anattached antenna is bioabsorbable in the patient's body. The associatedelectronics and/or antenna can be made either bioabsorbable orbiodegradable, or such that their presence does not have any significanteffect on the patient, or any combination thereof.

FIG. 11e shows a detailed view of an embodiment of sensor unit 1160. Thesensor unit is built into substrate 1180 which, in one embodiment, iscomposed of a bioabsorbable polymer as is known in the art. The sensorunit contains a communications device 1182 which is coupled to anantenna 1184. In certain embodiments, the antenna body is made of afully or partially bioabsorbable/biodegradable polymer, and containsconnected tubes that are filled with conductive and biocompatible gel orliquid. The communications device is biocompatible, and can bebioabsorbable. Coupled via 1188 to the communications device 1182 areone or more sensing elements 1186. The sensing elements can be of any ofthe type described earlier. In one embodiment, the sensing elements arefully or partially bioabsorbable/biodegradable. In certain embodiments,the sensing elements and communications device obtain electrical powerremotely from a radio frequency source, such as in RFID technology asknown in the art, and use this power to perform sensing operations andto transmit data to communications interface 1172. The embodiment shownin FIG. 11e is a representative configuration of the sensor unit; othertypes, shapes, and configurations are understood to be included as well.

In further embodiments of the present invention, an absorbable opticalfiber (such as shown in FIGS. 4a-e ) comprises at least a core and anouter cladding made out of bioabsorbable materials. Its layers can bemade out of bioabsorbable materials with different time constants fordegradation. For example, the cladding is thin but of a materialcomposition that degrades very slowly, and the core is of a compositionthat degrades very fast since once the cladding is degraded, the fiberis useless. This bioabsorbable optical fiber is used for the lightguides for optical sensors and/or for a communicative coupling betweenthe sensors and a controller.

FIGS. 12a-c shows a surgical staple or clip with integrated sensingcapabilities. The staple, clip, suture, or other fastener itself can beused as an electrode, as a strain or force sensor, or as an opticalpathway. Forces pulling on an anastomosis or other tissue joining cancause failure. By placing force measuring instrumentation on either astapler or other instrument's working surface, or on staples, clips,sutures, or other fasteners themselves, it is possible to measure thestrain induced on the tissue being joined.

FIG. 12a shows a staple with embedded sensors. The staple can includeany of the sensing modalities discussed earlier. In one embodiment,strain sensing for measuring the pulling or pushing forces exerted bytissue on the staple legs 1206 may be incorporated into the fastener. Inanother embodiment, strain gages 1204 are fabricated on the surface ofthe staple as 1204. In yet another embodiment, a coating or partiallayer of a piezoelectric or resistive coating 1224 is fabricated aroundstaple core 1222 as shown in cross-section A-A in FIG. 12b . In otherembodiments, the staple is a hollow tube 1224 whose inner core 1222 ismade of a piezoelectric, resistive, or other material or component thatpermits measurement or bending load on the staple legs 1206. This designis extendable to incorporating sensing capabilities into any surgicalfastener including staples, clips, and sutures. The staple, clip, orother fastener is made of in whole or in part ofbioabsorbable/biodegradable, biocompatible materials as known in theart.

FIGS. 13a-b depict embodiments where a staple, clip, or other electrodeis used for electrical sensing on the surface of a surgical instrument.FIG. 13a shows an embodiment where the instrument is used for tissueelectrical impedance sensing. The electrical resistance/impedance of thetissue can be used to indicate tissue properties. By measuringelectrical impedance of internal tissue at the surface of a surgicalinstrument, it is possible to determine the tissue's status includingindications of hypoxia and ischemia. Electrodes or electrical contactsplaced into the tissue are used as measurement points, the impedancemeasured between adjacent points and across any combination thereof.These electrodes are placed as small tips (invasive or surface contactonly) on the working surface of a surgical instrument.

The instrument surface 1302 contains one or more staples, clips, orother electrodes 1304 that act as electrical contacts. The electricalcontacts 1304 come in contact with tissue 1308 either on the surface orby penetrating into the tissue. The electrical impedance or resistancebetween the electrical contacts (either on the same staple or clip, orbetween adjacent or other pairs) is represented by 1310. Contacts areconnected via coupling 1312 to a controller 1314 where the measurementelectronics are housed. Coupling 1312 is either electrical, optical, orwireless. Additional surfaces, instruments, or opposing stapler orgrasper jaws 1320 contain additional electrodes 1322. They are coupledvia 1324 to an interface 1326 and further coupled via 1328 to the sameor a different controller 1314, or coupled directly to the controller1314.

FIG. 13b shows an embodiment where the instrument is used for tissueelectrical activity sensing, including nerve and muscle stimulation andsensing. Electrical activity in tissue can be used to assess thetissue's viability. The muscular and neuronal activity that occurs inthe tissue of interest is measured using techniques similar to those inelectromyography: either the naturally occurring activity, or theresponse to an excitation due to an electrical or other impulse.Implanting electrodes into the working surface of a surgical instrumentenables the viability of the local tissue to be quantified.

The instrument surface 1342 contains one or more staples, clips, orother electrodes 1344 that act as electrical contacts. The electricalcontacts 1344 come in contact with tissue 1346 either on its surface orby penetrating into the tissue. The contacts are coupled via 1348 to acontroller 1350 where the measurement electronics are housed. Coupling1350 is either electrical, optical, or wireless. Additional surfaces,instruments, or opposing stapler or grasper jaws 1352 contain additionalelectrodes 1354. They are coupled via coupler 1356 to an interface 1358and further coupled by coupler 1360 to the same or a differentcontroller 1350, or coupled directly to the controller 1314. Theelectrical contacts can be used for both sensing and/or stimulation ofthe tissue or components thereof. A separate electrical contact 1362 isplaced in tissue 1346. The separate contact can serve as a reference oras a source of nerve, muscle, or other stimulation that is sensed by theother electrical contacts 1344 and 1354. Reference contact 1362 iscoupled via coupler 1364 to the controller 1350.

FIG. 14 shows a schematic layout of an integrated expert systemaccording to the present invention. The base unit 1401 contains allprocessing, sensing, control, signal processing, communication, storage,and other required components. Coupled via coupler 1403 is sensingsurgical instrument(s) 1405. These instruments include, but are notlimited to, all of the instruments and embodiments describedhereinabove. Sensing modalities include, but are not limited to, any ofthose described herein, including oxygenation including oximetry-typesensing, fluorescence, tissue perfusion, general health, tissueelectrical impedance, tissue electrical activity, interaction forces,pH, electromyography, temperature, spectroscopy, fluid flow rateincluding laser or ultrasound Doppler measurement, fluid flow volume,pressure, levels of biomolecules and electrolytes, biomarkers,radiotracers, immunologic, chemical, nerve activity, evoked potential,and other sensor types capable of determining characteristics of tissue.Coupling 1403 is electrical, optical, and/or wireless. Instruments 1405are tethered via electrical or optical cables, have built in wirelessfunctionality, or have a reusable battery powered wireless pack thatpowers the instrument's sensors and/or the instrument itself, and/orcouples the signals to the base unit 1401. A reference measurementsensor 1415 of the same type as said surgical instruments and coupledvia coupler 1413 to base unit 1401 is used to obtain patient-specificreference measurements used to help determine tissue health and predictprocedural outcomes. In addition to the instruments, a roboticmanipulator useable to control the instruments and or reference sensoris coupled to the base unit 1401. The manipulator can be controlled in aclosed loop fashion to optimize procedural outcomes responsive toreal-time and prior patient specific information and prior statisticaland other data.

Patient status sensing including cameras, infrared imaging, thermalimaging, spectroscopic imaging, and other sources 1425 and operatingroom monitors 1435 including anesthesia equipment monitors and vitalsigns monitors which include, but are not limited to, pulse rate andquality measurement, respiration rate and quality measurement, bloodpressure measurement, blood gas analysis, pulse oximetry, and ECG, feedinto base unit 1401 via couplings 1423 and 1433 respectively. Thissystemic data is recorded and synchronized with that of the sensinginstruments, and also aids in determining tissue health and inpredicting procedural outcomes. The system can also be coupled viacoupling 1443 to the hospital's patient data storage system 1445 so thatcollected data is included in the database of patient medical historyinformation. Further, patient medical history is incorporated into thesystem's analysis of sensor data to better predict and optimizeoutcomes.

All relevant data collected and post-procedural outcomes are stored in acentral repository 1455 that is used to generate a statistical modelthat allows prediction of outcomes based on current sensor data. Thecoupling 1453 is bi-directional; prior data is used for analysis of thecurrent procedure and current patient data and outcomes are added to thedatabase 1455 for future use. Coupling 1453 need not be a permanentconnection; data in a local copy of 1455 can be retrieved from andupdated on each base unit 1401 at regular service intervals.

The collected data, statistical model, predicted outcomes, and otherrelevant information is presented in a comprehensible manner to thesurgeon or other operating room staff using one or more output devices1462 coupled to base unit 1401 via coupling 1460. Coupling 1460 is wiredor wireless, or output device 1462 can be integrated directly into thecontrol unit 1401. Presentation of results can be performed in numerousways including, but not limited to: visual feedback, audio feedback,force or other haptic feedback, or other forms of sensory substitution.The feedback can include plots, text-based messages, verbal messages,audible warnings, video overlays, and feedback on a robotic manipulator.Communication with an external database or other source of data isachieved with a communication device 1468 communicatively coupled to thebase unit 1401 via 1466. The coupling can be wired, wireless, or thecommunications device may be embedded in the base unit. Communicationsdevice 1468 can be a conventional modem, or an internet or other networkconnection.

The present invention can be practiced by employing conventionalmaterials, methodology and equipment. Accordingly, the details of suchmaterials, equipment and methodology are not set forth herein in detail.In the previous descriptions, numerous specific details are set forth,such as specific materials, structures, chemicals, processes, etc., inorder to provide a thorough understanding of the present invention.However, it should be recognized that the present invention can bepracticed without resorting to the details specifically set forth. Inother instances, well known processing structures have not beendescribed in detail, in order not to unnecessarily obscure the presentinvention.

Only an exemplary embodiment of the present invention and but a fewexamples of its versatility are shown and described in the presentdisclosure. It is to be understood that the present invention is capableof use in various other combinations and environments and is capable ofchanges or modifications within the scope of the inventive concept asexpressed herein.

1. A system comprising: a surgical instrument having a sensor forgenerating a signal indicative of a property of a subject tissue of apatient; a signal processor for receiving the signal and converting thesignal into a current dataset; a memory for storing the current dataset;and a processor configured to compare the current dataset with otherdatasets previously stored in the memory, and to assess a physicalcondition of the subject tissue or guide a current procedure beingperformed on the tissue, responsive to the comparison. 2-66. (canceled)